Substituted 2,5-dimethoxy- and 2,5-diphenoxy-1,4-benzoquinones react with o-aminophenols to give an equilibrium mixture of 2-phenylamino-5-methoxy(phenoxy)-1,4-benzoquinones and semiketals. The equilibrium depends on the substitution of the components and the solvent. The semiketals are transformed to 3-hydroxy-2-phenoxazones in acid solution.